Thailand

… The National Assembly, the Council of Ministers, Courts, Independent Organs and State agencies shall perform duties in accordance with the Constitution, laws and the rule of law for the common good of the nation and the happiness of the public at large. (Sec. 3)

The National Assembly consists of the House of Representatives and the Senate. … (Sec. 79)

The House of Representatives consists of five hundred members, as follows:
1. three hundred and fifty members elected on a constituency basis;
2. one hundred and fifty members from party lists of political parties.
In the case where the office of a Member of the House of Representatives becomes vacant for any reason, and an election of a Member of the House of Representatives has not been held to fill the vacancy, or no declaration of name of a Member of the House of Representatives has been made to fill the vacancy, the House of Representatives shall consist of the existing members of the House.
In the case where there is any reason for the number of the Members of the House of Representatives by party list basis to be fewer than one hundred and fifty persons, the Members of the House of Representatives by party list basis shall consist of the existing members. (Sec. 83)

Members of the House of Representatives who are elected on a constituency basis shall be elected by direct suffrage and secret ballot. ... (Sec. 85)

A candidate in an election of a Member of the House of Representatives on a constituency basis, must be a person nominated by a political party of which he or she is a member, and shall not stand for election in more than one constituency. … (Sec. 87)

A person having the following qualifications has the right to stand for an election of Members of the House of Representatives:
1. being of Thai nationality by birth;
2. being not less than twenty-five years of age up to the date of the election;
3. being a member of any and only one political party for a consecutive period of not less than ninety days up to the date of the election; however, in the case where the general election is conducted due to the dissolution of the House of Representatives, the period of ninety days shall be reduced to thirty days;
4. a candidate in an election on a constituency basis shall also have any one of the following qualifications:
a. having his or her name appear in the household register in the Changwat where he or she stands for election for a consecutive period of not less than five years up to the date of applying for candidacy;
b. being born in the Changwat where he or she stands for election;
c. having studied in an educational institution situated in the Changwat where he or she stands for election for a consecutive period of not less than five academic years;
d. having served in the official service or performed duties in a State agency, or having had his or her name appear in the household register in the Changwat where he or she stands for election, as the case may be, for a consecutive period of not less than five years. (Sec. 97)

The Senate consists of two hundred members installed from a selection by and among persons having the knowledge, expertise, experience, profession, or characteristics or common interests or working or having worked in varied areas of the society. ... (Sec. 107)

A Senator shall have the qualifications and not be under any of the prohibitions as follows:
a. qualifications:
1. being of Thai nationality by birth;
2. being not less than forty years of age on the date of application for selection;
3. having knowledge, expertise and experience, or having worked for not less than ten years in the field for which he or she applies, or having the qualifications under the rules and conditions prescribed in the Organic Act on Installation of Senators;
4. being born, having his or her name listed in the household register, having worked or having a connection to the area in which he or she applies for selection in accordance with the rules and conditions prescribed in the Organic Act on Installation of Senators;
... (Sec. 108)

There shall be the following organic acts:
1. Organic Act on Election of Members of the House of Representatives;
2. Organic Act on Installation of Senators;
… (Sec. 130)